/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.geode.management.internal.beans.stats;

import org.apache.geode.management.internal.beans.MetricsCalculator;

/**
 * 
 *
 */
public class StatsRate {
  
  private long prevLongCounter = 0;
  
  private int prevIntCounter = 0;

  private MBeanStatsMonitor monitor;
  
  private String[] statsKeys;
  
  private StatType type;

  
  
  public StatsRate(String statsKey, StatType type, MBeanStatsMonitor monitor) {
    this.statsKeys = new String[] { statsKey };
    this.monitor = monitor;
    this.type = type;
  }

  public StatsRate(String[] statsKeys, StatType type, MBeanStatsMonitor monitor) {
    this.statsKeys = statsKeys;
    this.monitor = monitor;
    this.type = type;
  }

  public float getRate() {
    long currentTime = System.currentTimeMillis();
    return getRate(currentTime);
  }

  public float getRate(long pollTime) {
    float rate = 0;
    switch (type) {
    case INT_TYPE:
      int currentIntCounter = getCurrentIntCounter();
      rate = currentIntCounter - prevIntCounter;
      prevIntCounter = currentIntCounter;
      return rate;
    case LONG_TYPE:
      long currentLongCounter = getCurrentLongCounter();
      rate = currentLongCounter - prevLongCounter;
      prevLongCounter = currentLongCounter;
      return rate;
    default:
      return rate;
    }
  }

  private int getCurrentIntCounter() {
    int currentCounter = 0;
    for (String statKey : statsKeys) {
      currentCounter += monitor.getStatistic(statKey).intValue();
    }
    return currentCounter;
  }

  private long getCurrentLongCounter() {
    long currentCounter = 0;
    for (String statKey : statsKeys) {
      currentCounter += monitor.getStatistic(statKey).longValue();
    }

    return currentCounter;
  }

}
